Synthesis of nanocrystalline diamond from glassy carbon balls

• Published in: Journal of crystal growth 2015-02, Vol.412, p.54-59
• Main Authors: Solopova, N.A., Dubrovinskaia, N., Dubrovinsky, L.
• Format: Article
• Language: English
• Subjects: A1. Raman spectroscopy; A1. Recrystallization; B1. Diamond; B1. Glassy carbon balls; B1. Nanomaterials; B3. Multianvil apparatus; Chemical compounds; Crystal growth; Diamonds; Glassy carbon; Magnesium oxide; Nanocrystals; Scanning electron microscopy; Static pressure; Synthesis
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2014.11.041

Here we report the high-pressure and high-temperature synthesis of nanocrystalline diamond (NCD) from glassy carbon balls using a multianvil apparatus. Different chemical compounds were used as the synthesis and pressure transmitting media. A detailed characterization of the synthesized products was performed using optical microscopy, Raman spectroscopy and scanning electron microscopy (SEM). Fully optically transparent nanocrystalline diamond micro-balls and lenses with complete optical transparency and the size of about 15–40μm were synthesized at a static pressure of 18GPa in the temperature range of 1850–2000°С using MgO as a pressure medium. •Series of experiments aimed at high pressure synthesis of nanocrystalline diamond (NCD) balls were conducted using glassy carbon as a precursor.•NCDs micro-balls were synthesized at pressure of 18GPa and temperatures above 1500°C.•We found that pressure medium and PT parameters of experiments influence on the quality of obtained diamond material.•Target properties of the balls (optical transparency, homogeneity, and integrity) were reached only in experiments with MgO as a pressure medium.